The present invention relates to a fixing liner, composed of a textile liner web, which is coated on one side with double-layer adhesive mass points, which are made up of lower points, facing the liner web, and upper points, arranged above them.
From the document, European Patent A 0 940 461, a cross-linkable hot-melt adhesive mass is known for coating and/or laminating textile fabrics, in which a cross-linking component is bound in a polyolefin matrix, and the reactive components only react in the melted mass under conditions of cross-linking. As cross-linking components, isocyanates or epoxides having molar masses between 2000 and 6000 grams per mol are indicated. The actual hot-melt adhesive mass, in this context, is composed of amino-terminated co-polyamides or copolyesters, which are used both in the lower and in the upper points. Disadvantageous in this solution is the fact that, for one thing, the cross-linking components must first be bound in a polyolefin matrix, which protects against humidityxe2x80x94an expensive processxe2x80x94, and that the amino-terminated co-polyamides have a strong tendency to yellow.
Furthermore, from the document, U.S. Pat. No. 5,677,038, a double-layer hot-melt adhesive mass is known, whose lower point is made up of a co-polyamide or copolyester, applied in paste form, and whose upper point is made up of a mixture of 0 to 25% by weight of a co-polyamide, 50 to 95% by weight of a copolyester, and 5 to 25% by weight of an epoxide. As separation forces for the textile materials bonded using this hot-melt adhesive system, values under 10 N/5 cm are indicated, which are further reduced after a washing. In addition to the cited documents, other double-layer adhesive masses are known from the documents, German Patent A 22 14 236, German Patent A 22 31 723, German Patent A 25 36 911, and German Patent A 32 30 579. By using relatively light nonwoven fabrics, i.e., those having a small mass per unit area, it is indeed possible to obtain very soft laminates, but nonwoven fabrics have the disadvantage that they are sensitive with regard to the reverse attaching of the hot-melt adhesive masses. In this context, reverse attaching is understood to mean an undesirable adhesion between two liner materials, which can occur when the liner web coated with the adhesive point mass, hereinafter termed the fixing liner, is bonded to the upper material in the inner-sandwich fixing method. In this context, the inner sandwich is composed of the layer sequence, upper material, coated liner web, and coated liner web, upper material, i.e., so that the uncoated sides of the liner webs contact one another. It is true that the quantity of coating which was applied per square meter of liner web was reduced from 18-25 g/m2 to 7-15 g/m2 and should have been reduced even further in view of the breathing capacity of the textile laminate. Nevertheless, the demands on the adhesion and strength of the laminate are increasing at the same time. In particular, with respect to the characteristics regarding the routine care of a textile laminate, there is the requirement that the laminate be able to survive many washings at temperatures of up to 60xc2x0 C.
It is an object of the present invention to provide a fixing liner which demonstrates significantly increased adhesive and separating forces while at the same time showing very low reverse attaching tendencies.
This and other objects of the invention are achieved by a fixing liner, composed of a textile liner web (1), which is coated on one side with double-layer adhesive mass points, which are made up of lower points, facing the liner web, and upper points (2, 3), arranged above them, in which lower points (2) are made up of a powdery mixture of 25 to 90% by weight of an epoxide resin having an epoxide equivalent weight of 500 to 4000 mVal/kg and 10 to 75% by weight of an acid-terminated polyamide, a polyester, a polyurethane and/or a vinyl copolymer having carboxyl, anhydro, hydroxy, and/or amido side groups and having a melt flow index (MFI) of 40 to 120 g/10 min measured at 160xc2x0 C. and 2.16 kg, 0 to 20% by weight of a hardener as well as the auxiliary and filler materials that are customarily used to produce a paste, and upper points (3) are made up of acid-terminated polyamides and/or copolyesters, the weight ratio of the masses contained in lower and upper points (2, 3) amounting to 1:0.5 to 1:5. Using the fixing liners according to the present invention, separating force values are achieved that are 50% or, especially after washing at temperatures of 60xc2x0 C., more than 100% greater than those of fixing liners manufactured using the known double-layer adhesive masses.